The invention relates to a filling valve for dispensing flowable masses with a sealing piston which is disposed in a housing and comprises at least one sealing edge which is movably disposed in the region of and can control at least one dispensing opening which is provided in the housing.
For example, such filling valves are employed in order to fill suitable vessels with flowable filling products. They can find utilization in order to dispense milk in metered quantities in packaging units, for example, cups. Furthermore, one can also take into consideration dispensable products which constitute a mixture of several partial products, for example, stirrable yogurt or yogurt with fruits.
Filling valves which were heretofore employed for such purposes comprises a sealing piston which can be moved through a housing substantially in a vertical direction. In order to open the filling valve, the sealing piston is moved out of the housing and a filling opening in a direction toward the vessel to be filled. After the vessel has been filled, the sealing piston is again pulled back into the housing. During such movement of the sealing piston, the stream of the material to be dispensed and flowing through the dispensing opening is supposed to be sheared off by the correspondingly configurated edges of the sealing piston within the dispensing opening.
Problems arise in connection with such filling valves especially when such filling valves are to dispense mixtures of different partial products. In such instances, one can assume that, during closing of the dispensing opening, solid constituents of the products to be dispensed become wedge between the sealing piston and the dispensing opening in the course of the closing step. In order to prevent such wedging, the edges surrounding the dispensing opening on the one hand and the edges of the sealing piston on the other hand are as sharp as possible in order to establish the conditions for shearing off the solid constituents by the moving sealing piston in the dispensing opening. However, such shearing effect does not develop in many instances because, in view of the yieldable mounting of the sealing piston and its relatively long unguided portion, one cannot avoid that the piston is deflected by the solid constituent to be sheared off within the dispensing opening. Portions of solid constituents which are to be sheared off are wedged during movement of the sealing piston between the piston and the dispensing opening and cause the development of a leak spot through which the liquid constituents of the product to be dispensed can trickle even at the times when a vessel to be filled is located beneath the dispensing opening. The product to be dispensed drips from the only partially sealed dispensing opening onto the guide elements on which the vessels to be filled are transported to positions beneath the dispensing opening or onto the vessels themselves to thus prevent a sealing of the vessels.